{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "pyjwt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "pyjwt"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.13.0-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode() or jwt.decode_complete() are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature verification is performed with the algorithm bound to the PyJWK object instead of the header algorithm. An attacker who controls a registered JWK/JWKS private key can sign with a disallowed algorithm, advertise an allowed algorithm in the JWT header, and still be accepted. The issue affects the documented PyJWKClient.get_signing_key_from_jwt(...) flow. This vulnerability is fixed in 2.13.0.",
  "id": "DEBIAN-CVE-2026-48523",
  "modified": "2026-09-17T08:47:30.177050209Z",
  "published": "2026-05-28T16:16:29.280Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-48523"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-48523"
  ]
}